1. Field of the Invention
This invention relates generally to the fields of biochemistry and medicine, and more specifically to compounds useful as antiviral and antimicrobial agents.
2. Background Information
Viral infections have long been and continue to be a major cause of human suffering. The large variety of viruses combined with the diverse types of afflictions continue to challenge endeavors to find and make available agents capable of treating or mitigating the effects viral infections.
One family of viruses that is particularly troublesome is the Herpes simplex viruses (HSV). HSV is a relatively common human pathogen which can cause fatal disease in the young or immunocompromised. HSV includes two closely related variants designated type 1 (xe2x80x9cHSV-1xe2x80x9d) and type 2 (xe2x80x9cHSV-2xe2x80x9d). These types cross react strongly, but can be distinguished by neutralization titrations. HSV-1 and HSV-2 are responsible for a variety of human diseases, such as skin infection, fever blisters, genital herpes, viral encephalitis, and the like. Both HSV-1 and HSV-2 have been shown to be capable of causing neonatal infections. HSV-2 genital infections has been linked with the development of cervical cancer.
Cytomegalovirus (CMV) is another member of the HSV family. CMV infection is the leading cause of congenital viral infections with an incidence averaging 1% of all live births. An additional 5% to 10% of infants acquire CMV perinatally as a result of mother-to-infant transmission. Although the virus is widely distributed in the population about 40% of women enter pregnancy without antibodies and thus are susceptable to infection. CMV infections of the eye have resulted in the loss of sight to immunocomprised individuals afficted with AIDS. CMV infection is also a major concern organ transplant recipients, especially, kidney and liver transplants.
A major avenue for HSV transmission is through skin to skin contact with an infected area, such as genital to genital contact, and contact to the eye with the hands. It is therefore desirable to administer a potent antiviral, particularly, anti-HSV or anti-CMV agent topically prior to potential viral introduction into an individual.
Because of these disease conditions, there is a continuing effort made by individual academic investigators, and by small and large pharmaceutical companies to identify new and useful antiviral agents. Various drug discovery strategies have been developed. In some instances, derivatives of known effective drugs are prepared and examined for improved or different, but useful, characteristics. Another approach is to develop or acquire large libraries of randomly synthesized drugs candidates, and screen these compounds for potential efficacy as antiviral agents. Both of these methods have resulted in the identification of potentially useful antiviral agents. Yet another approach has been to identify potentially useful drugs that are produced naturally by living organisms. For example, paclitaxel is a chemical that is produced by the yew tree and, when purified, is effective in treating cancers such as ovarian carcinoma. Applying a similar discovery strategy, naturally occurring agents with antiviral activity are being sought and screened for antiviral activity.
A naturally occurring compound has been recently discovered, which surprisingly possesses antiviral activity, and fulfills the needs of the requirements for an antiviral agent.
The present invention provides a compound having the structure: 
wherein,
R1a and R1b are independently selected from the group consisting of xe2x80x94H, alkyl, lower-alkyl, substituted alkyl and substituted lower-alkyl;
R2a and R2b are independently selected from the group consisting of xe2x80x94H, lower-alkyl, and substituted lower-alkyl;
R3 is xe2x80x94H, lower-alkyl, substituted lower-alkyl and where R3 and R4 are attached together by a lower-alkyl or a substituted lower-alkyl moiety;
R4 is xe2x80x94H, lower-alkyl, substituted lower-alkyl and where R3 and R4 are attached together form a lower-alkyl or substituted lower-alkyl bridge;
R5, R7, R9 and R11 are independently selected from the group consisting of xe2x80x94H, lower-alkyl, and substituted lower-alkyl;
R6 is xe2x80x94H, lower-alkyl and substituted lower-alkyl;
R8 is xe2x80x94H, lower-alkyl and substituted lower-alkyl;
R10 is xe2x80x94H, lower-alkyl and substituted lower-alkyl;
R12 is xe2x80x94H, lower-alkyl and substituted lower-alkyl; and
A is xe2x80x94C(O)xe2x80x94R13, wherein R13 is xe2x80x94H, xe2x80x94OH, alkyl, lower-alkyl, substituted lower-alkyl or xe2x80x94O(lower-alkyl); xe2x80x94CH2xe2x80x94OR14 wherein R14 is xe2x80x94H, xe2x80x94C(O)CH3, alkyl, lower-alkyl or substituted lower-alkyl; or xe2x80x94CH2xe2x80x94NR15R16, where R15 and R16 are independently selected from xe2x80x94H, lower-alkyl, alkyl, substituted lower-alkyl or substituted alkyl;
a pharmaceutically acceptable salt or derivatives thereof, useful for preventing and treating viral and microbial infections.
The present invention provides method for treating viral infections, in particular, herpes simplex type I and II viral infections and cytomegalovirus.
The present invention provides a compound having the structure: 
wherein,
R1a and R1b are independently selected from the group consisting of xe2x80x94H, alkyl, lower-alkyl, substituted alkyl and substituted lower-alkyl;
R2a and R2b are independently selected from the group consisting of xe2x80x94H, lower-alkyl, and substituted lower-alkyl;
R3 is xe2x80x94H, lower-alkyl, substituted lower-alkyl and where R3 and R4 are attached together by a lower-alkyl or a substituted lower-alkyl moiety;
R4 is xe2x80x94H, lower-alkyl, substituted lower-alkyl and where R3 and R4 are attached together form a lower-alkyl or substituted lower-alkyl bridge;
R5, R7, R9 and R11 are independently selected from the group consisting of xe2x80x94H, lower-alkyl, and substituted lower-alkyl;
R6 is xe2x80x94H, lower-alkyl and substituted lower-alkyl;
R8 is xe2x80x94H, lower-alkyl and substituted lower-alkyl;
R10 is xe2x80x94H, lower-alkyl and substituted lower-alkyl;
R12 is xe2x80x94H, lower-alkyl and substituted lower-alkyl; and
A is xe2x80x94C(O)xe2x80x94R13, wherein R13 is xe2x80x94H, xe2x80x94OH, alkyl, lower-alkyl, substituted lower-alkyl or xe2x80x94O(lower-alkyl); xe2x80x94CH2xe2x80x94OR14 wherein R14 is xe2x80x94H, xe2x80x94C(O)CH3, alkyl, lower-alkyl or substituted lower-alkyl; or xe2x80x94CH2xe2x80x94NR15R16, where R15 and R16 are independently selected from xe2x80x94H, lower-alkyl, alkyl, substituted lower-alkyl or substituted alkyl;
a pharmaceutically acceptable salt or derivatives thereof, useful for preventing and treating viral and microbial infections.
The invention provides a method for preventing and treating viral infections, such as, HSV-1, HSV-2 and CMV.
In addition, the invention provides a method for preventing and treating microbial infections.
Further, the invention provides a method of treating viral infections in combination with antiviral agents, such as, acyclovir, penciclovir, valaciclovir, famciclovir, ganciclovir and foscarnet.
Still further, the invention provides a method of preventing and treating,viral infection in combination with antiviral topical agents, such as, nonoxynol.
As used herein the term xe2x80x9calkylxe2x80x9d refers to a branched or straight chain monovalent saturated aliphatic hydrocarbon radical of seven to twenty carbon atoms. This term is further exemplified by such radicals as n-heptyl, n-decyl, n-tridecyl and the like.
As used herein, the term xe2x80x9clower-alkylxe2x80x9d refers to a branched or straight chain monovalent alkyl radical of one to six carbon atoms. This term is further exemplified by such radicals as methyl, ethyl, propyl, isopropyl, butyl (for example, isobutyl, t-butyl, or n-butyl), pentyl (for example, 2-methylbutyl, 3-methylbutyl), and hexyl (for example, 2-methylpentyl, 2,2-dimethylbutyl and 2,3-dimethylbutyl).
As used herein, the term xe2x80x9csubstituted alkylxe2x80x9d refers to an alkyl moiety optionally substituted with hydroxy, carbonyl, carboxy, halide, amidyl, guanidyl, thio and carboxyamide. Example of substituted alkyl moieties, include but are not limited by, tetradecanoyl, nonylcarbonyl, and 1-chloropentylcarbonyl.
As used herein the term xe2x80x9csubstituted lower-alkylxe2x80x9d refers to a lower-alkyl moiety optionally substituted with hydroxy, carbonyl, carboxy, halide, amidyl, guanidyl, thio, and carboxyamide. Examples of substituted lower-alkyl moieties, include but are not limited by, methoxycarbonyl, 4-aminobutyl, and 4-guanidylpropyl.
As used herein, the term xe2x80x9clower-alkyl bridgexe2x80x9d or xe2x80x9csubstituted lower-alkyl bridgexe2x80x9d refers to a lower-alkyl moiety optionally substituted with hydroxy, carbonyl, carboxy, halide, acidyl, linked such that it forms a moiety within the peptide backbone of the compound. For example where R3 and R4 together are linked by a propyl group, the resultant lower-alkyl bridge with R3 and R4 forms the cyclopentyl functional group of proline; or where R3 and R4 together form a 2-hydroxypropyl group, the resultant lower-alkyl bridge with R3 and R4 forms the hydroxycyclopentyl functional group of hydroxyproline.
As used herein, the following terms refer to the corresponding organic moieties,
xe2x80x9ccarboxylxe2x80x9d refers to xe2x80x9cxe2x80x94C(O)Oxe2x80x94xe2x80x9d;
xe2x80x9cacetylxe2x80x9d or xe2x80x9cAcxe2x80x9d refers to xe2x80x9cCH3xe2x80x94C(O)xe2x80x94xe2x80x9d; and
xe2x80x9cacetoxyxe2x80x9d or xe2x80x9cAcOxe2x80x9d refers to xe2x80x9cCH3xe2x80x94C(O)xe2x80x94Oxe2x80x94.xe2x80x9d
As used herein, the term xe2x80x9cisolatedxe2x80x9d or xe2x80x9csubstantially purexe2x80x9d means that the compound of the invention is at least about 50% free of materials with which it normally is associated in a cell, particularly CNL240, and generally is about 90% or 95% free of such materials, particularly at least 99% free of such material.
As used herein, the term xe2x80x9csaltxe2x80x9d or pharmaceutically-acceptable saltxe2x80x9d encompasses those salts that form with the carboxylate anions and includes salts formed with the organic and inorganic cations such as those chosen from the alkali and alkaline earth metals, (for example, lithium, sodium, potassium, magnesium, barium and calcium); ammonium ion; and the organic cations (for example, dibenzylammonium, benzylammonium, 2-hydroxyethylammonium, bis(2-hydroxyethyl)ammonium, phenylethylbenzylammonium, dibenzylethylenediammonium, and like cations.) Other cations encompassed by the above term include the protonated form of procaine, quinine and N-methylglucosamine, the protonated forms of basic amino acids such as glycine, ornithine, histidine, phenylglycine, lysine, and arginine. Furthermore, any zwitterionic form of the instant compounds formed by a carboxylic acid and an amino group is referred to by this term. A preferred cation for the carboxylate anion is the sodium cation. Further included are salts that form by standard acid-base reactions with basic groups (such as amino groups), including organic or inorganic acids. Such acids include hydrochloric, sulfuric, phosphoric, acetic, succinic, citric, lactic, maleic, fumaric, palmitic, cholic, palmodic, mucic, D-glutamic, D-camphoric, glutaric, phthalic, tartaric, lauric, stearic, salicylic, methane sulfonic, benzenesulfonic, sorbic, picric,;benzoic, cinnamic acids, and the like.
The compounds of the above structure may also exist as solvates and hydrates. Thus, these compounds may crystallize with, for example, waters of hydration, or one, a number of, or any fraction thereof of molecules of the mother liquor solvent. The solvates and hydrates of such compounds are included within the scope of this invention.
As used herein, the term xe2x80x9chydroxy-protecting groupxe2x80x9d refers to readily cleavable groups bonded to hydroxyl groups, such as the tetrahydropyranyl, 2-methoxyprop-2-yl, 1-ethoxyeth-1-yl, methoxymethyl, xcex2-methoxyethoxymethyl, methylthiomethyl, t-butyl, t-amyl, trityl, 4-methoxytrityl, 4,4xe2x80x2-dimethoxytrityl, benzyl, allyl, 4,4xe2x80x2,4xe2x80x3-trimethoxytrityl, trimethylsilyl, (t-butyl)dimethylsilyl, 2,2,2-trichloroethoxycarbonyl, and the like. Further examples of hydroxy-protecting groups are described by Reese and Haslam, xe2x80x9cProtective Groups in Organic Chemistryxe2x80x9d (McOmie, Ed., Plenum Press, New York, N.Y., 1973), Chaps. 3 and 4; and Greene and Wuts, xe2x80x9cProtective Groups in Organic Synthesis,xe2x80x9d Second Edition (John Wiley and Sons, New York, 1991), Chaps. 2 and 3; each of which is incorporated herein by reference. A preferred hydroxy-protecting group is the tert-butyl group. The related term xe2x80x9cprotected hydroxyxe2x80x9d denotes a hydroxy group bonded to one of the above hydroxy-protecting groups.
As used herein, the term xe2x80x9camino-protecting groupxe2x80x9d as used herein refers to substituents of the amino group commonly employed to block or protect the amino functionality while reacting other functional groups of the molecule. The term xe2x80x9cprotected (monosubstituted)-aminoxe2x80x9d means there is an amino-protecting group on the monosubstituted amino nitrogen atom. Examples of such amino-protecting groups include the formyl group, the trityl group, the phthalimido group, the trichloroacetyl group, the trifluoroacetyl group, the chloroacetyl, bromoacetyl, and ibdoacetyl groups, urethane-type protecting groups, such as t-butoxycarbonyl (xe2x80x9cBocxe2x80x9d), 2-(4-biphenylyl)propyl-2-oxycarbonyl, 2-phenylpropyl-2-oxycarbonyl, 2-(4-xenyl)isopropoxycarbonyl, 1,1-diphenylethyl-1-oxycarbonyl, 1,1-diphenylpropyl-1-oxycarbonyl, 2-(3,5-dimethoxyphenyl)propyl-2-oxycarbonyl, 2-(p-toluyl) propyl-2-oxycarbonyl, cyclopentanyloxycarbonyl, 1-methylcyclopentanyl-oxycarbonyl, cyclohexanyloxycarbonyl, 1-methyl-cyclohexanyloxycarbonyl, 2-methylcyclohexanyl-oxycarbonyl, 2-(4-toluylsulfonyl) ethoxycarbonyl, 2-(methylsulfonyl)ethoxycarbonyl, 2-(triphenylphosphino)-ethoxycarbonyl, 9-fluorenylmethoxycarbonyl (xe2x80x9cFmocxe2x80x9d), 2-(trimethylsilyl)ethoxycarbonyl, allyloxycarbonyl, 1-(trimethylsilylmethyl)prop-1-enyloxycarbonyl, 5-benzisoxalylmethoxycarbonyl, 4-acetoxybenzyloxycarbonyl, 2,2,2-trichloroethoxycarbonyl, 2-ethynyl-2-propoxycarbonyl, cyclopropylmethoxycarbonyl, isobornyloxycarbonyl, 1-piperidyloxycarbonyl, benzyloxycarbonyl (xe2x80x9cCbzxe2x80x9d), 4-phenylbenzyloxycarbonyl, 2-methylbenzyloxycarbonyl, 4-methoxybenzyloxycarbonyl, xcex12,4,5,-tetramethylbenzyl-oxycarbonyl, 4-fluorobenzyloxycarbonyl, 4-chlorobenzyloxycarbonyl, 3-chlorobenzyloxycarbonyl, 2-chlorobenzyloxycarbonyl, 2,4-dichlbrobenzyloxycarbonyl, 4-bromobenzyloxycarbonyl, 3-bromobenzyloxycarbonyl, 4-nitrobenzyloxycarbonyl, 4-cyanobenzyloxycarbonyl, 4-(decyloxy)benzyloxycarbonyl and the like; the benzoylmethylsulfonyl group, the 2,2,5,7,8-pentamethylchroman-6-sulfonyl group, the dithiasuccinoyl group, the 2-(nitro)phenyl-sulfenyl group, the diphenylphosphine oxide group, and like amino-protecting groups. The species of amino-protecting group employed are not critical so long as the derivatized amino group is stable to the conditions of the subsequent reaction(s) and can be removed at the appropriate point without disrupting the remainder of the molecule. Preferred amino-protecting groups are Boc, Cbz and Fmoc. Further examples of amino-protecting groups embraced by the above term are well known in organic synthesis and the peptide art and are described, for example, by Greene and Wuts, supra, 1991, Chap. 7; Bodanzsky, xe2x80x9cPrinciples of Peptide Synthesis,xe2x80x9d St. and 2nd revised Ed. (Springer-Verlag, New York, 1984 and 1993); Stewart and Young, xe2x80x9cSolid Phase Peptide Synthesis,xe2x80x9d 2nd Ed. (Pierce Chemical Co., Rockford Ill., 1984); Atherton and Shephard, xe2x80x9cSolid Phase Peptide Synthesisxe2x80x94A Practical Approachxe2x80x9d (IRL Press, Oxford England, 1989), each of which is incorporated herein by reference. The related term xe2x80x9cprotected aminoxe2x80x9d defines an amino group substituted with an amino-protecting group discussed above.
As used herein, the term xe2x80x9camino acidxe2x80x9d refers to an organic chemical compound or moiety that contains both a basic amino group and an acidic carboxylic group. Alpha amino acids are where the amino group is attached to the alpha carbon. Amino acids are the primary structural units of peptides and proteins. Amino acids can be classified into three classes based on the charge status of the R group, that is, apolar R, uncharged polar R, charged R, as listed below the twenty most common naturally occurring amino acids.
Alternatively, amino acids can be classified according to their acid/base characteristics, that is, neutral, basic or acidic.
As used herein, the term xe2x80x9cAibxe2x80x9d refers to the amino acid 2-aminoisobutyric acid, which has the corresponding structure, 
As used herein, the term xe2x80x9cLeu(OH)xe2x80x9d refers to the structure, 
As used herein, the xe2x80x9cderivativexe2x80x9d of a polypeptide or protein refers to a polypeptide or protein where its amino acid sequence is altered by one or more amino acids. The derivative may have xe2x80x9cconservativexe2x80x9d changes, wherein a substituted amino acid has similar structural or chemical properties, e.g., substitution of an apolar amino acid with another apolar amino acid (such as replacement of leucine with isoleucine). The derivative may also have xe2x80x9cnonconservativexe2x80x9d changes, wherein a substituted amino acid has different but sufficiently similar structural or chemical properties that permits such a substitution without adversely effecting the desired biological activity, e.g., replacement of an amino acid with an uncharged polar R group with an amino acid with an apolar R group (such as replacement of glycine with tryptophan), or alternatively replacement of an amino acid with a charged R group with an amino acid with an uncharged polar R group (such as replacement of lysine with asparagine).
Similar minor modifications may also include amino acids deletions or insertions or both. Guidance in, determining which amino acid residues may be modified as indicated above without abolishing the desired biological functionality may be determined using computer programs well known in the art, for example, DNASTAR software. In addition, the derivative may also result from chemical modifications to the encoded polypeptlide, including but not limited to the following, replacement of hydrogen by an alkyl, acyl, or amino group; esterification of a carboxyl group with a suitable-alkyl or aryl moiety; alkylation of a hydroxyl group to form an ether derivative. Further a derivative may also result from the substitution of a L-configuration amino acid with its corresponding D-configuration counterpart. Another strategy for derivatizing peptides, polypeptides and proteins is to alter the structure of specific amino acids. For example, the carboxy moiety can be reduced to hydroxy group, such as in the conversion of leucinol for leucine; where an additional methyl group can be substituted to the xcex1-carbon atom, such as in the conversion of alanine to amino-isobutyric acid; or where a hydroxy group is substituted to the 4 position of proline resulting in the conversion of proline to 4-hydroproline.
As used herein, the term xe2x80x9cmimeticxe2x80x9d refers to a molecule, the structure of which has conformational similarity to the structure of a protein/polypeptide or portions thereof and, as such, is able to effect some or all of the actions of the peptide, polypeptide or protein.
Depending on the choice of solvent and other conditions known to the practitioner skilled in the art, compounds of this invention may also take the ketal or acetal form, which forms are included in the instant invention. In addition, it should be understood that the equilibrium forms of the compounds of this invention may include tautomeric forms. All such forms of these compounds are expressly included in the present invention.
The compounds of the invention can be modified by appropriate functionalities to enhance selective biological properties. Such modifications are known in the art and include those which increase biological penetration into a given biological system, for example, blood, the lymphatic system, or the central nervous system, increase oral availability, increase solubility to allow administration by injection, alter metabolism and alter rate of exertion. In addition, the compounds can be altered to a pro-drug form such that the desired compound is created in the body of the patient as the result of the action of metabolic or other biochemical processes on the pro-drug. Some examples of pro-drug forms include ketal, acetal, oxime, and hydrazone forms of compounds which contain ketone or aldehyde groups.
One of ordinary skill in the art will recognize that the compounds of the present invention can be described and named following accepted nomenclature for peptides. The stereoconfiguration of the xcex1-carbon of a residue is indicated by the letters L or D preceding the three-letter code for the residue. Graphically, the stereoconfiguration about a chiral center is designated by either a solid or hatched wedge shaped bonds. For the textual convention, the absence of a letter or the presence of both letters indicates a mixture of the L and D isomers, or that diastereomers were separated but not identified. In a similar manner, the presence of a non-wedged bond indicates a mixture of the L and D isomers, or that diastereomers were separated but not identified.
Some representative compounds are named in the following examples.
For example, Halovir A can be depicted by following structure, 
wherein,
R1a is tetradecanoyl;,
R1b is xe2x80x94H;
R2a and R2b are methyl;
R3 and R4 are attached together by 2-hydroxypropyl;
R5, R7, R9 and R11 are H;
R6 and R12 are 2-methylpropyl;
R8 is 2-propyl;
R10 is 3xe2x80x2-propionyl acid amide; and
A is xe2x80x94CH2xe2x80x94OR14 where R14 is H;
as well as by, CH3(CH2)12C(O)-Aib-Hyp-Leu-Val-Gln-Leu(OH), with the corresponding specific structure, 
For example, Halovir B can be depicted by following structure, 
wherein,
R1a is tetradecanoyl;
R1b is xe2x80x94H;
R2a and R2b are methyl;
R3 and R4 are attached together by 2-hydroxypropyl;
R5, R7, R9 and R11 are H;
R6 and R12 are 2-methylpropyl;
R8 is methyl;
R10 is 3xe2x80x2-propionyl acid amide; and
A is xe2x80x94CH2xe2x80x94OR14 where R14 is H;
as well as by, CH3(CH2)12C(O)-Aib-Hyp-Leu-Ala-Gln-Leu(OH) with the corresponding specific structure, 
For example, Halovir C can be depicted by the structure, 
wherein,
R1a is tetradecanoyl;
R1b is xe2x80x94H;
R2a and R2b are methyl;
R3 and R4 are attached together by propyl;
R5, R7, R9 and R11 are H;
R6 and R12 are 2-methylpropyl;
R8 is 2-propyl;
R10 is 3xe2x80x2-propionyl acid amide; and
A is xe2x80x94CH2xe2x80x94OR14 where R14 is H;
as well as, CH3(CH2)12C(O)-Aib-Pro-Leu-Val-Gln-Leu(OH) (SEQ. ID. NO.: 1), with the corresponding specific structure, 
For example, Halovir D can be depicted by the following structure, 
wherein,
R1a is tetradecanoyl;
R1b is xe2x80x94H;
R2a and R2b are methyl;
R3 and R4 are attached together by 2-acetoxypropyl,
R5, R7, R9 and R11 are H;
R6 and R12 are 2-methylpropyl;
R8 is 2-propyl;
R10 is 3xe2x80x2-propionyl acid amide; and
A is xe2x80x94CH2-OAc;
as well as, CH3(CH2)12C(O)-Aib-Hyp(OAc)-Leu-Val-Gln-Leu(OAc), with the corresponding specific structure, 
For example, Halovir E can be depicted by the following structure, 
wherein,
R1a is tetradecanoyl;
R1b is xe2x80x94H;
R2a and R2b are methyl;
R3 and R4 are attached together by 2-hydroxypropyl;
R5, R7, R9 and R11 are H;
R6 and R12 are 2-methylpropyl;
R8 is methyl;
R10 is 3xe2x80x2-propionyl acid amide; and
A is xe2x80x94C(O)OCH3;
as well as, CH3(CH2)12C(O)-Aib-Hyp-Leu-Val-Gln-Leu-OMe), with the corresponding specific structure, 
As used herein, the term xe2x80x9chalovirxe2x80x9d refers to a family of hexapeptides and hexapeptide like compounds isolated from the fermentation of the marine fungus Scytalidium sp. CNL240 from a sample of the seagrass Halodule wrightii collected from the Bahamas. The marine fungus has been deposited with the American Type Culture Collection ATCC Designation No. 74470 (Manassas, Va.).
The present invention includes substantially purified compounds isolated from the fermentation of the marine fungus, Scytalidium sp. CNL240 and also includes derivatives of halovir. In addition to availability from a natural source, halovirs can be synthesized using conventional techniques as disclosed herein (see Examples 2 and 3). Advantageously, these compounds are conveniently synthesized from readily available starting materials. As disclosed herein, compounds of the invention, halovirs A to C, can also be isolated in substantially purified form from Scytalidium sp. CNL240 and then can be chemically modified as desired to obtain derivative of the original compounds, such as Halovir D and Halovir E, to add one or more of the substituents discussed above. In steps calling for natural seawater, artificial formulas can be used as a substitute. As used herein, the term xe2x80x9cisolatedxe2x80x9d or xe2x80x9csubstantially purifiedxe2x80x9d means that the compound of the invention is at least about 50% free of materials with which it normally is associated in a cell, particularly Scytalidium sp. CNL240 and generally is about 90% or 95% free of such materials, particularly at least 99% free of such material.
If desired, a compound of the invention can be in the form of a pharmaceutical composition, comprising the compound or a salt thereof, and pharmaceutically acceptable excipient(s). As used herein, the terms xe2x80x9cpharmaceutically acceptablexe2x80x9d and xe2x80x9cphysiologically acceptablexe2x80x9d are intended to have the same meaning. Pharmaceutically acceptable excipients, which can be an adjuvant or other vehicle, include, but are not limited to, ion exchange resins, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin; buffer substances such as the various phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids; water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, and zinc salts; colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyarylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat, and the like.
A compound of the invention, when administered to a subject such as a mammalian subject, for example, a human, can be administered orally, parenterally, by inhalation, topically, rectally, nasally, buccally or vaginally, and can be contained in an implanted reservoir. Parenteral administration can be by subcutaneous, intracutaneous, intravenous, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intralesional or intracranial injection or by an infusion method.
A compound of the invention, which can comprise a pharmaceutical composition, can be in the form of a sterile injectable preparation, for example, a sterile injectable aqueous or oleaginous suspension. Such a suspension can be formulated by methods known in the art using, for example, suitable dispersing or wetting agents such as Tween 80, or suspending agents. The sterile injectable preparation also can be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be employed are mannitol, water, Ringer""s solution and isotonic saline solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil can be employed, including synthetic monoglycerides or diglycerides. Fatty acids such as oleic acid and its glyceride derivatives also are useful in the preparation of injectables, as are natural pharmaceutically acceptable oils such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions also can contain a long chain alcohol diluent or dispersant.
A compound of the invention can be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets and aqueous suspensions and solutions. In the case of tablets for oral use, carriers that commonly are used include lactose and corn starch. Lubricating agents such as magnesium stearate also can be added. For oral administration in capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are administered orally, the active ingredient can be combined with emulsifying and suspending agents. If desired, certain sweetening, flavoring or coloring agents can be added.
A compound of the invention also can be formulated in a pharmaceutical composition for administration in the form of suppositories for rectal administration. Such a composition can be prepared by mixing a compound of the invention, for example, halovir, with a suitable non-irritating excipient that is solid at room temperature, but liquid at the rectal temperature. Such materials include, but are not limited to, cocoa butter, beeswax and polyethylene glycols.
Topical administration of a compound of the invention can be particularly useful when the desired treatment involves areas or organs readily accessible to topical application. For application topically to the skin, for example, the compound should be formulated with a suitable ointment containing the active compound suspended or dissolved in a carrier, or can be in the form of a spray. Carriers for topical administration of the compounds of the invention include, but are not limited to, mineral oil, liquid petroleum, white petroleum, propylene glycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax and water. A compound of the invention also can be formulated with a suitable lotion or cream containing the active compound suspended or dissolved in a carrier. Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. A compound also can be formulated to allow topical application to the lower intestinal tract by rectal suppository formulation or in a suitable enema formulation. Topically applied transdermal patches and eye drop formulations containing a compound of the invention are also included in this invention.
A compound of the invention also can be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well known in the art of pharmaceutical formulation and can be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, or other solubilizing or dispersing agents.
A compound of the invention can be advantageously administered with other antiviral agents, such as, acyclovir, penciclovir, valaciclovir, famciclovir, ganciclovir and foscarnet. Further the invention can be further administered in combination the antiviral agents listed above with other topical antiviral agents, such as nonoxynol or the like. A pharmaceutical composition of matter comprising such a combination would possess the advantage of being able to address the viral infection along diverse but yet effective avenues as provided by the beneficial characteristics of the individual components of the combination, thus allowing for a great collective syngergistic benefit to the afflicted subject.